The AVL 8-Mode test is a steady-state engine test procedure designed to closely correlate with the exhaust emission results over the US FTP transient cycle for heavy-duty engines, especially in regards to NOx emissions. The test involves 8 steady state modes. The composite value is calculated by applying weighing factors on the modal results.
The sequential engine operating points are as follows:
|Mode||% Engine Speed*||% Load||Weight factor†|
|* Normalized speed: 0% = low idle, 100% = rated speed|
† Relative weight factors, not normalized (they do not add to 100%)
The relative weights of particular modes are represented by the area of bubbles in Figure 1.
Figure 1. AVL 8-Mode Heavy-Duty Cycle